AS Rock Z77 Extreme4 not recognizing Sapphire Radeon HD 7850 OC

[Zeorn]

I have recently built a new computer and everything works fine other than the connection between my motherboard and graphics card. The ASRock Z77 Extreme4 motherboard worked with my old graphics card and the Sapphire Radeon HD 7850 OC worked on my old motherboard, but they won't work together. I thought it might be my power supply because I had a larger supply on my old computer, so I swapped the 750W power supply to my new computer and it still didn't work.

I have found similar threads in these forums yet they are either not responded to or if they are the problem is never clearly resolved.
Example: Asrock Z77 extreme 6 doesn't detect my Sapphire HD 7850 GPU
One person says he got a replacement graphics card and that fixed the problem, but then another states it was a problem in a switch on the motherboard.

It will recognize the card if I switch the PCIE3 from Auto to Gen1 in UEFI, but that isn't really a solution and it also seems to reset to Auto so you have to keep changing it back.

If both work fine with other motherboard and graphics card then it has to be some compatibility issue between the two that creates this sort of anomaly. Considering the same thing was happening with other similar motherboards I'm thinking it is the Z77 chipset.

Any support to figure out this problem would be appreciated.

[kpo6969]

I run the same board and card with no issues so you may have a defective board.

[synack]

I have recently built a new computer and everything works fine other than the connection between my motherboard and graphics card. The ASRock Z77 Extreme4 motherboard worked with my old graphics card and the Sapphire Radeon HD 7850 OC worked on my old motherboard, but they won't work together. I thought it might be my power supply because I had a larger supply on my old computer, so I swapped the 750W power supply to my new computer and it still didn't work.

I have found similar threads in these forums yet they are either not responded to or if they are the problem is never clearly resolved.
Example: Asrock Z77 extreme 6 doesn't detect my Sapphire HD 7850 GPU
One person says he got a replacement graphics card and that fixed the problem, but then another states it was a problem in a switch on the motherboard.

It will recognize the card if I switch the PCIE3 from Auto to Gen1 in UEFI, but that isn't really a solution and it also seems to reset to Auto so you have to keep changing it back.

If both work fine with other motherboard and graphics card then it has to be some compatibility issue between the two that creates this sort of anomaly. Considering the same thing was happening with other similar motherboards I'm thinking it is the Z77 chipset.

Any support to figure out this problem would be appreciated.

From that link you provided, I believe it was determined to be a faulty video card and/or video card firmware. The posters said that a replacement card fixed the issue.